herb is a continuation of the medullary substance of the root; the principle of the flowers and leaves is the same, because both spring from the tissue-layers surrounding the pith, as Cesalpino had taught. The statement which follows, that the principle of the bud and the leaves is identical, would be a departure from Cesalpino, and in any case inconsistent, without the explanation that the bud consists of rudimentary leaves; but this again puts the axial portion of the bud out of sight. The perianth, he says, comes from concrescent rudiments of leaves. How closely Linnaeus adhered to Cesalpino in his later years appears in his explanation of the catkin, which comes next and which is taken entirely from Cesalpino's theory. That a more superficial and a more profound conception pursue their way together unadjusted in Linnaeus' speculations on form is specially shown by the fact, that in the text of the 'Philosophia Botanica,' paragraph 84, he places the 'stipulae' under the idea of 'fulcra' and not under that of 'folia,' while on the contrary at the end of the same work, where he brings together the different paragraphs respecting metamorphosis, he speaks of the 'stipulae' as appendages of the leaves.
The idea of Cesalpino, that the parts of the flower which surround the fruit arise like the ordinary leaves from the tissues that enclose the pith, is further developed by Linnaeus in his 'Metamorphosis Plantarum,' in the fourth volume of the 'Amoenitates Academicae' (1759), in a very strange manner. He compares the formation of the flower with the metamorphosis of animals, and especially of insects, and after describing the changes that take place in animals, he says at page 370 that plants are subject to similar change. The metamorphosis of insects consists in the putting off different skins, so that they finally come forth naked in their true and perfect form. This metamorphosis we also find in most plants, for they consist, at least in the truly living part of the root, of rind, bast, wood, and pith. The rind is to the plant what the skin is to the larva of an insect, and after putting this skin off there
